November ii, 1909] 



NA TURE 



>o 



dogmatic way that is so destructive of their interest 

 uid advancement. The classification of animals 

 adopted, Unicellularia, Radiata, Bilateralia, is almost 

 as antique as that of the animal and vegetative 

 functions maintained in the earlier part of this book. 

 The "worms" are reduced to a type characterised by 

 a trochosphere-larva and nephridia, whilst, for the 

 benefit of medical students, only parasitic forms are 

 described. The book is, in fact, a compilation of the 

 "cram" order, and is devoted mainly to the structure 

 and life-history of parasites. In no single instance is 

 the scale of a figure given. 



(2) In spite of the very large output of books on 

 biology, there is still no modern work in which the 

 factors of the life of plants are correlated with those 

 of animal life in a broad and intimate manner. This 

 text-book is, perhaps, as near an approach to such a 

 treatment as the limits of a cheap school-book allow, 

 and in the sroond edition just issued the breadth of 

 treatment has been increased. The contents are 

 divided into three parts. First come the relations of 

 iTg'anisms to environment; then follows an account 

 of structure and functions ; lastly, a brief chapter on 

 jjsvchology and anthropology. Between the last two 

 parts is a short, clear account of evidence for the 

 theory of descent. Of these three sections, the first is 

 undoubtedly the most novel for a work of this kind. 

 It is very doubtful whether the author has not 

 attempted to compress far too much information into 

 these pages, and certainly the attempt to teach the 

 subject from such a book as this without simplifying 

 its contents would be disastrous. The work itself 

 appears to be a well-illustrated summary of facts, but 

 is as hard to assimilate as a concentrated foodstuff. 

 The teacher must supply the zymogen. 



(3) In this American book the experience of the pro- 

 fessional "aquarist" and importer has been combined 

 with that of the practised amateur. The result is a 

 solume full of interesting matter and of practical 

 suggestion to naturalists and teachers. The introduc- 

 tion of many beautifully coloured fish from Texas, 

 Florida, India, and other countries into the northern 

 States enables a very great choice of interesting sub- 

 jects to be drawn upon. The climbing perch, the 

 "shooter" that brings its prey down by spitting, and 

 the lovely Paradise fish Macropodes, the nests of which 

 are readily constructed in captivity, are some of the 

 more striking oriental fish introduced by one of the 

 authors. The Reptilia and Amphibia are also fully 

 considered, and the book concludes with most useful 

 advice on the choice of natural and artificial foods. In 

 these days of experimental stations and school labora- 

 tories, such a practical guide as this should be very 

 welcome. The illustrations are excellent, and the only 

 fault we have to find with the' work is its weight, 

 which not only splits the binding, but tires the hand. 



(4) The value of this little book lies in the fact that 

 its descriptions of the occurrence and habits of ants 

 are largely written down from the author's observa- 

 tion. The sketches are thrown into a conversational 

 form so as to appeal to children. The various beetles 

 found in ants' nests are fully considered and figured, 

 and the author is evidently acquainted with the litera- 

 ture of the subject. We can heartily recommend this 



NO. 2089, VOL. 82] 



little book as a record of long and patient observation, 

 and as a very useful risume of the most distinctive 

 and interesting features in the life of these highly 

 organised animals. 



(5) Dr. von Linstow's popular account of human 

 and animal parasites ends badly from the beginning. 

 On the cover of the book there is a gruesome picture 

 of infected pond-life, and a tragedy occurs on almost 

 every page. The contents describe some appalling 

 cases of the course of parasitical diseases, and whilst 

 we fully acknowledge the abundant knowledge and 

 clear exposition that has gone to its making, we can 

 hardly believe that such a treatise is appropriate to a 

 series suitable for children and people generally. Pan 

 certainly has a terrifying aspect when seen thus, and 

 it would have relieved the depression if the available 

 prophylactic and remedial measures could, as far as 

 possible, have been described. 



ELEMENTARY PHYSICS. 

 (i) An Introduction to Physical Science. By Dr. 



F. H. Getman. Pp. ix + 257. (New York : J. Wiley 



and Sons; London : Chapman and Hall, Ltd., 1909.) 



Price 6s. 6d. net. 

 (2) An Elementary Course in Practical Science. Part 



iii. By C. Foxcroft and S. J. Bunting. Pp. 



64. (London : G. Philip and Son, Ltd., n.d.) Price 



6d. net. 

 (l)' I 'HE book by Dr. Getman is intended for those 

 J- students who, owing to little knowle'dge of 

 physics, find it difficult to understand lectures on 

 general chemistry. It deals in a brief manner with 

 all the usual sections of physics, with the exception 

 of sound. It is in many respects an admirable book. 

 The chief laws and principles are in most cases very 

 clearly expressed. As an example of this, attention 

 may be directed to the concise and unambiguous treat- 

 ment of the distinction between " mass " and 

 "weight." The diagrams are good, and logical 

 order is preserved. There is no doubt that a student 

 thoroughly conversant with the contents would have 

 little difficulty with his chemistry from a physical 

 point of view. On the other hand, we think that for 

 several reasons the book itself presents difllculties. 

 The definitions, particularly in the first chapter or two, 

 are sometimes rather loose. Matter is apologetically 

 defined as " that which occupies space," a statement 

 which is worthless. Surely a better provisional defini- 

 tion is "matter is that which has weight," and then 

 the extension of "weight" to "gravitational attrac- 

 tion " could follow at a later stage. Again, a solid is 

 defined as "a body which at ordinary temperatures 

 does not change its shape under slight changes of 

 pressure." This is untrue. There is no distinction, 

 except in degree, between solids and fluids in this 

 respect. The terms " stress " and " strain " are in- 

 sufficiently defined, being merely given as alternatives 

 for force and distortion respectively. 



We feel, too, that the cutting out of detail, which 

 the author admits in the preface, has been carried 

 too far. The descriptions of experiments are thus in 

 many cases vague, and in a few instances actually 

 misleading. For example, in the determination of the 



